Endoscope designs and methods of manufacture

ABSTRACT

Various embodiments of the present invention comprise endoscopes for viewing inside a cavity of a body such as a vessel like a vein or artery. These endoscopes may include at least one solid state emitter such as a light emitting diode (LED) that is inserted into the body cavity to provide illumination therein. Certain embodiments of the invention comprise disposable endoscopes that can be fabricated relatively inexpensively such that discarding these endoscopses after a single use is cost-effective. The endoscope may comprise a lens holder on a distal end of the endoscope for collection of light reflected from surfaces within the body in which the endoscope is inserted. This lens holder may have an inner cavity through which light passes along an optical path. Reflective surfaces on sidewalls of the inner cavity may direct light along this optical path. The endoscope may further comprise an elongated support structure for supporting a plurality of lenses disposed along the optical path. This optical path may lead to a detector onto which images are formed.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/099,435, filed Apr. 5, 2005, now U.S. Pat. No. 7,976,462, whichclaims the benefit of U.S. Provisional Application No. 60/559,813, filedApr. 6, 2004, all of which are incorporated by reference herein.

BACKGROUND

1. Field of the Invention

The present invention relates generally to optical systems, and in someembodiments, to endoscopes and other medical devices.

2. Description of the Related Art

Endoscopes generally include a tube with imaging optics to be insertedinto a patient. Illumination may be provided by a source that is locatedexternal to the patient. Light from the illumination source may travelvia a conduit, such as a fiberoptic or fiberoptic bundle, through thetube into the patient. The light may be emitted inside of the patient atthe tube's distal end near a treatment or viewing site. Features insidethe body are likewise illuminated and can be viewed using the imagingoptics, which form images of the patient's insides.

SUMMARY

In one embodiment, an endoscope has proximal and distal end portions forviewing inside a cavity of a body. The endoscope comprises: one or moresolid state emitters having an electrical input and an optical output,said one or more solid state emitters disposed at said distal endportion of said endoscope, said one or more solid state emittersradiating light when activated so as to illuminate at least a portion ofsaid cavity in said body; an optical path extending from said distal endportion to said proximal end portion for propagating light from saiddistal end portion to said proximal end portion of said endoscope suchthat an image of an object at said distal end portion can be formed atsaid proximal end portion; and an electrically conducting path from saidproximal end portion to said distal end portion of said endoscope, saidelectrically conducting path electrically connected to said electricalinput of said one or more solid state emitters for providing electricalpower to said one or more solid state emitters.

In another embodiment, an endoscope has proximal and distal end portionsfor viewing features inside a body into which said distal end portion ofsaid endoscope is inserted. The endoscope comprises: a longitudinalmember extending from said distal end portion to said proximal endportion, said longitudinal member having an inner cavity region; anoptical path through said inner cavity region of said longitudinalmember for propagating light from said distal end portion to saidproximal end portion of said endoscope; and a first specularlyreflective metalized non-glass surface disposed along said optical pathat said distal end portion of said longitudinal member, said firstspecularly reflective metalized surface angled such that light can becollected at said distal end portion from an oblique direction withrespect of said longitudinal member.

In yet another embodiment, a battery operated hand-held endoscopeinstrument has proximal and distal end portions for producing images ofinternal regions of a body. The endoscope instrument comprises: one ormore solid state emitters having an electrical input and an opticaloutput, said one or more solid state emitters disposed at said distalend portion of said endoscope instrument, said one or more solid stateemitters for illuminating said internal regions of said body; an opticalpath extending from said distal end portion to said proximal end portionfor propagating light from said distal end portion to said proximal endportion of said endoscope instrument to form an image at said proximalend portion; an electrically conducting path from said proximal endportion to said distal end portion of said endoscope, said electricallyconducting path electrically connected to said electrical input of saidone or more solid state emitters for providing electrical power from abattery at said proximal end portion to said one or more solid stateemitters at said distal end portion; an optical sensor disposed at saidproximal end portion of said endoscope, said optical sensor comprisingan optical sensor having an electrical power input and electrical signaloutput; and a wireless transmitter electrically connected to saidelectrical signal output of said optical sensor so as to receiveelectrical signals from said electrical signal output of said opticalsensor corresponding to images formed on said optical sensor.

In one embodiment, a endoscope has proximal and distal ends for viewingfeatures inside a body. The endoscope comprises: a plurality of rodlenses aligned along an optical path; a slotted elongate supportstructure comprising a plurality of slots in which said plurality of rodlenses respectively fit so as to be aligned along said optical path; andan outer tube with a hollow inner region, said elongated supportstructure together with said plurality of rod lens disposed in saidhollow inner region of said out tube, wherein said slots are separatedwith respect to each other so as to establish suitable spacing betweensaid lenses to relay an image of a feature in said body to said proximalend portion.

In another embodiment, a method of manufacturing an endoscope assemblyfor viewing portions of a body, said endoscope assembly having a distalend portion and a proximal end portion, comprises: providing anelongated support structure having a plurality of sites for insertion ofoptical elements; inserting a plurality of lenses at said sites;inserting said elongated support structure into a hollow outerprotective shield having an open inner region, wherein said plurality ofsites are laterally positioned and longitudinally spaced from withrespect to each other so as to provide an aligned optical system thatrelays an image from said distal end portion to said proximal endportion.

In another embodiment, a method of manufacturing a front end of anendoscope for viewing portions of a body comprises: forming a frontendpiece, said front endpiece for receiving light from said bodyportions to enable viewing of said body portions; forming an innercavity region in said front endpiece, said inner cavity region forpassage of said light from said body portions; forming at least onesubstantially planar sidewall surface in said inner cavity region; andmetalizing said at least one substantially planar sidewall surface so asto form a substantially reflective surface that reflects said lightreceived from said body portions.

In yet another embodiment, a head for an endoscope for viewing objectscomprises: a main body having a front and a rear, said front to bedisposed with respect to said object such that light from said objectpropagates toward said front of said main body; an inner open region insaid main body, light from said object propagating into said inner openregion, said inner open region defined by interior sidewalls of saidmain body; and apertures at said front and rear of said main bodyproviding access to said inner open region, wherein at least one of saidsidewalls is coated with a substantially reflective material and issubstantially smooth so as to form a substantially reflective surface,said reflective surface reflecting light from said object such that animage of said object can be formed.

In one embodiment, a disposable endoscope for viewing features inside abody comprises: a longitudinal member having distal and proximal endsand an inner cavity region therein, said longitudinal member furthercomprising an end portion at said distal end with an aperture thereinfor entry of light into said inner cavity, at least said end portioncomprising plastic; one or more solid state emitters disposed at saiddistal end of said longitudinal member for providing illumination; andan optical path through said inner cavity region of said longitudinalmember for propagating light from said distal end to said proximal endof said longitudinal member, said optical path including at least oneoptical element, wherein said end portion of said longitudinal memberincludes reflective material formed on said plastic in said end portionof said longitudinal member to reflect light received through saidaperture along said optical path to said proximal end portion of saidlongitudinal member.

In another embodiment, a disposable endoscope for viewing featuresinside a body comprises: a longitudinal member having distal andproximal ends and an inner cavity region therein, said longitudinalmember further comprising an end portion at said distal end with anaperture therein for entry of light into said inner cavity, at leastsaid end portion comprising ceramic material; one or more solid stateemitters disposed at said distal end of said longitudinal member forproviding illumination; and an optical path through said inner cavityregion of said longitudinal member for propagating light from saiddistal end to said proximal end of said longitudinal member, saidoptical path including at least one optical element, wherein said endportion of said longitudinal member includes reflective material formedon said ceramic material in said end portion of said longitudinal memberto reflect light received through said aperture along said optical pathto said proximal end portion of said longitudinal member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one system for producing images of features inside ofbody parts;

FIG. 2 illustrates another system for producing images of featuresinside of body parts;

FIG. 3 is an exploded perspective view of a longitudinal membercomprising an endoscope structure;

FIG. 4 is a rear perspective view of an exemplary front lens holder thatmay be used with the longitudinal member of FIG. 3;

FIG. 5 shows a schematic diagram of an optical path through a frontsurface tilted at an angle with respect to a rear surface;

FIG. 6 shows another view of a front lens holder for used with alongitudinal member, such as the longitudinal member of FIG. 3;

FIG. 7 is a perspective view of an elongated support structure, whichmay be used as the cradle of FIG. 3; and

FIG. 8 is a partial perspective view of an exemplary slotted elongatesupport structure, which may also be used as the cradle of FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the present invention comprise endoscopes for viewinginside a cavity of a body such as a vessel like a vein or artery orelsewhere. The endoscopes have a light source that is configured, sizedand positioned so as to be inserted into the body cavity to provideillumination therein. In various embodiments, this light sourcecomprises at least one solid state emitter such as a light emittingdiode (LED). Preferably, this solid state emitter is small and bright.Light emitted from the light source is reflected off objects or walls inthe interior of the body cavity. A portion of the reflected light iscollected through an aperture in the endoscope. This light is directedalong an optical path through the endoscope so as to form an image ofthe objects or walls. In certain embodiments, the optical path includesa series of lenses such as rod lenses disposed in a support structure orcradle. The light is then directed to an optical sensor such as, forexample, an optical detector array or an optical camera. Thus, an imageof the object inside the body cavity can be viewed.

FIG. 1 illustrates one system 100 according to an embodiment of theinvention for producing images such as electronic, e.g., video ordigital, images of features inside, for example, body parts. The system100 includes an endoscope structure 110 coupled to an imaging andcontrol apparatus 114 through a cable 112. The imaging and controlapparatus 114 includes an optical sensor 116, a processor 118, a display120, a power supply 122, and a power control 124.

The endoscope structure 110 comprises an elongated member that isinserted into a portion of a body such as a human body. This endoscopestructure 110 includes a distal end portion 126 and a proximal endportion 128. One or more solid state emitters (not shown) are preferablydisposed at the distal end portion 126. The solid state emitters eachinclude an electrical input and have an optical output. The solid stateemitters may comprise, for example, light emitting diodes (LEDs).Preferably, these solid state emitters are bright and small. In someembodiments, for example, these solid state emitters radiate over 10lumens. These LED may be less than a millimeter and in some embodimentsmay be about 0.5 millimeters. The large brightness and small size ofthese emitters enables such endoscopes to have a smaller cross-sectionthan conventional endoscopes that rely on large optical fiber bundles toprovide illumination. Reduced size offers the advantage that theendoscope is less intrusive and causes less damage and trauma to thebody. A plurality of such small solid state emitters may be disposed atthe distal end of the endoscope structure 110. In certain embodiments 2,3, 4, 5, 6, 7, 8, or more emitters are employed. In some embodiments,these emitters emit white light although emitters need not be whitelight emitters. Colored emitters and emitters that radiate in narrowwavelength ranges may be employed as well. For example, images may beformed by optical sensors 116 that are sensitive to the particularwavelength region used for illumination. In certain embodiments, aspecific wavelength illumination may be employed for fluorescenceapplications.

The solid state emitters radiate light and illuminate a portion of abody cavity. Accordingly, the distal end 126 of the endoscope structure110 includes an aperture (not shown) for collecting light reflected orscattered from the illuminated portion of the body cavity. The lightcollected through the aperture is transferred along an optical path (notshown) from the distal end 126 of the endoscope structure 110 to theproximal end 128. Preferably, features in the illuminated portion of thecavity are imaged and the image is relayed along the optical path so asto form an image of a portion of the body cavity at the proximal end128.

Accordingly, the light and image are transferred from the proximal end128 of the endoscope structure 110 through the cable 112 to the imagingand control apparatus 114. Accordingly, the cable preferably comprises asystem of relay lens or a coherent fiber bundle. The cable preferablytransfers the image to the optical sensor 116 in the imaging apparatus114. The optical sensor 116, which may comprise a detector array such asa CCD or CMOS sensor array, has a light sensitive optical input thatreceives the light from the cable 112. The optical sensor 116 preferablyfurther comprises an electrical signal output for outputting anelectrical signal corresponding to the image of the illuminated portionof the body cavity. The electrical signal from the optical sensor 116 istransmitted to a processor 118 and onto a on the display device 120 suchas a video screen or computer monitor. Although not shown, alternativeembodiments may include transmitting the electrical signal from theoptical sensor 116 directly to the display device 120, for example, whenthe optical sensor 116 performs the processing.

As discussed above, in certain embodiments the cable 112 comprises afiber optic such as a coherent fiber optic bundle. The cable 112 alsopreferably includes electrical power lines (not shown), such as thinelectrical leads or wires, that provide electrical power to the solidstate emitters disposed at the distal end 126 of the endoscope 110. Theelectrical power lines are electrically coupled to the power supply 122.This power supply 122 may, for example, provide 12 or 24 volts and 20milliamps to 1.5 Amp of current, however, voltages and currents outsidethese ranges are possible. The power supply 122 may be controlled by thepower controller 124. The power controller 124 may, for example, enablethe current supplied to the solid state emitters at the distal end 126of the endoscope structure 110 to be adjusted. Accordingly, thebrightness or intensity of the light emitted from the solid stateemitters can be adjusted. In one embodiment, the power control comprisesa rheostat.

Although the cable 112 is included in the endoscope system 100 shown inFIG. 1, this cable is not required. In other embodiment, this cable 112may be excluded. For example, the optical sensor 116 may be disposed atthe proximal end portion 128 of the endoscope structure 110. In suchdesigns, electrical cable may be connected to the endoscope structure110 to power the one or more solid state emitters at the distal endportion 126.

In certain embodiments, the endoscope structure 110 is disposable.Various design features discussed more fully below may reduce the costof the endoscope structures 110 such that the endoscope structure neednot be reused over and over but may be discarded after use. In someembodiments, the endoscope structure 110 may plug into the cable 112 andthus may be detached and disposed of and replaced for the nextprocedure.

FIG. 2 illustrates a system 200 that offers increased ease of use. Thesystem 200 includes an endoscope structure 220, a receiver 222, aprocessor 224, and a display device 226. The endoscope shown in FIG. 2,however, is a battery operated, hand-held instrument which is configuredto produce images of internal regions of a body as described above. Theendoscope structure 220 shown includes a distal end 230 and a proximalend 232 and one or more solid state emitters (not shown) at the distalend that emit light to illuminate internal regions of the body. Thedistal end 230 of the endoscope structure 220 further includes anaperture (not shown) for collecting light emitted from the solid stateemitters and reflected off of the internal regions of the body. Anoptical path (not shown) extends from the distal end 230 of theendoscope structure 220 to a proximal end 232.

At the proximal end 232 of the endoscope structure 220 is an opticalsensor 234, a transmitter 236, a battery 238, and a control device 240.The optical sensor 234 is disposed to receive collected light and moreparticularly, an image of a portion of the body, and to provide anelectrical signal output. At the proximal end 232, the light collectedat the distal end 230 forms an image on the optical sensor 234 whichproduces an electrical output corresponding to the image of theilluminated internal region of the body. The electrical signal issupplied to the transmitter 236, which transmits the signal to thereceiver 222. The transmitter 236 and the receiver 222 are preferablywireless. In various embodiments, the transmitter 236 comprises an RFtransmitter and the receiver 222 comprises an RF receiver. The receiver222 provides the received signal to the processor 224 that feeds signalsto the display device 226. In some embodiments, the processor 224 mayformat the received signal so that the image of the illuminated internalregion of the body can be displayed. This processor 224 may also provideadditional image processing. In alternative embodiments, the opticalsensor 234 provides the necessary formatting and processing and thereceived signal is transferred directly from the receiver 222 to thedisplay device 226. Other distributions of functions between electronicsin the optical sensor 234 and processor 224 are possible.

The battery 238 is electrically coupled to the transmitter 236, theoptical sensor 234 and to the solid state emitters disposed at thedistal end 230 of the endoscope structure 220. The control device 240may be configured to allow a user of the endoscope to control the amountof current supplied by the battery 238 to the solid state emittersdisposed at the distal end 230 of the endoscope structure 220. In anembodiment, the control device 240 is also configured to allow the userto selectively apply or remove a power signal from the battery 238 tothe transmitter 236 and solid state emitters. This controller device 240may comprise, for example, a rheostat or potentiometer, or digitalswitch, in certain embodiments. The control device may comprise aintegrated circuit chip, such as a microprocessor, in certainembodiments.

The optical sensor 234, transmitter 236, and battery 238 disposed at theproximal end 232 of the endoscope structure 220 allows the endoscopestructure to be a self-contained instrument that is easily maneuverableand readily mobile. The endoscope structure 220 does not need to beattached with wires or cables to provide power or to carry an image orsignal to processing and display instruments. The user therefore hasincreased freedom to manipulate the endoscope structure and is nottethered to a console or power supply that would otherwise restrict therange of movement during a procedure. As described above, in variousembodiments, the endoscope structure 220 is disposable. In an certainembodiments, the endoscope structure 220, including the solid stateemitters, is disposable and is detachable from the optical sensor 234,transmitter 236, battery 238, and control device 240, which arereusable. Various design features help reduce the cost of the endoscopestructure 110 and enable disposal and replacement to be a competitivealternative to reuse.

FIG. 3 illustrates an exploded perspective view of a longitudinal member300 comprising an endoscope structure, according to various embodimentsof the invention. The longitudinal member 300 has a distal end 320 and aproximal end 322. The longitudinal member 300 has a hollow inner cavityregion 324 which provides an optical path from the distal end 320 to theproximal end 322.

A plurality of solid state emitters 326 (five shown) are disposed at thedistal end 320 of the longitudinal member 300. In various embodiments,the solid state emitters 326 each comprise an LED. The solid stateemitters are configured to emit light into the body.

At the distal end 320, the longitudinal member 300 includes a front lensholder 328 having a front surface 332 with seats to receive the solidstate emitters 326. The front lens holder 328 also includes a channeltherethrough that comprises a portion of the inner cavity region 324 ofthe longitudinal member 300. Front and rear apertures in the front lensholder 328 provide access to the channel and a path through the lensholder 328. Illumination reflected from portions of the body proceedsthrough this channel along this optical path. Preferably, the front lensholder 328 is configured to hold a front lens 330 that collectsreflected light from the solid state emitters 326 into the inner cavityregion 324 of the front lens holder 328. In certain preferredembodiments, the front surface 332 is angled so that light can becollected at the distal end 320 from an oblique direction with respectto the longitudinal member 300. For example, the longitudinal member 300may be used to observe an inner side wall of a vessel such as a vein orartery by inserting the longitudinal member 300 longitudinally into thevessel and rotating the longitudinal member 300 such that the tiltedfront surface 332 is directed towards a portion of the inner side wallof the vessel desired to be imaged.

The longitudinal member 300 further includes a cradle 340 that isattachable to the front lens holder 328. The cradle 340 is configured tobe a support structure for at least one optical element in the opticalpath from the distal end 320 of the longitudinal member 300 to theproximal end 322 of the longitudinal member 300. In various embodiments,the cradle 340 is configured to support and align multiple lens elements342 (five shown). The lens elements 342 may comprise, for example, rodlenses. The cradle 340 is an elongated support structure comprising ahollow cylindrical tube with portions of the tube removed to form slots344 (five shown). In various embodiments, the slots 344 are sized,configured, and positioned to receive the lens elements 342 and to alignthe lens elements 342 automatically along the optical path in the innercavity region 324. Moreover, the slots 344 are preferably spaced apartto provide the appropriate spacing of the lens 342 along a longitudinaldirection and optical axis as defined by the lens prescription.

The longitudinal member 300 further comprises an outer tube 350. Theouter tube 350 includes an inner region 352 and an outer region 354.With the lens elements 342 disposed in the slots 344 of the cradle 340,the cradle 340 can be slid into the inner region 352 of the outer tube350. The outer tube 350 may shield and protect the cradle 340 and lenselements 342.

In certain embodiments, the outer region 354 of the outer tube 350comprises a heat conducting material such as aluminum, stainless steel,or the like. In such an embodiment, the outer tube 350 may conduct heatgenerated by the solid state emitters 326 away from the distal end 320of the longitudinal member 300. In other embodiments, other portions ofthe outer tube 350, the cradle 340, and/or lens holder 328 may comprisethermally conducting material. Conductive material may be deposited onthe outer tube 350, the cradle 340 and/or the lens holder 328 in certainembodiments. For example, these components may comprise ceramic orplastic with portions having metallization formed thereon by, forexample, electroplating or electrochemically deposition. In certainembodiments, the outer tube 350 comprises stainless steel and a portionof this outer tube 350 is electroplated with aluminum for heatconduction and/or electrical connection. Other designs are possible.

Although not shown, a diffuser or a plurality of diffusers may bedisposed in front of the solid state emitters 326. The diffuser orplurality of diffusers are configured to disperse the light from thesolid state emitters 326.

In operation, at least the distal end 320 of the longitudinal member 300is inserted into a body cavity. An electrical power signal is providedto the solid state emitters 326 by thin electrical wires (not shown) orelectrical traces (not shown) that may be disposed along a surface ofthe cradle 340 and front lens holder 328. The electrical power signalcauses the solid state emitters 326 to emit light having an intensityproportional to the electrical power signal. In the case where thelongitudinal member 300 comprise conducting material such as metal, theconducting longitudinal member 300 may operated as an electrical pathfor providing power or grounding to the emitters 326.

The light is reflected off an object within the body cavity or the innerwalls of the body cavity. A portion of the reflected light is collectedinto the inner cavity region 324 of the front lens holder 328 through anaperture (not shown) in the front surface 332. As discussed above, thelight may be collected by a front lens 330. The light is then directedthrough the plurality of lens elements 342 disposed in the cradle 340.Thus, the light propagates from the distal end 320 of the longitudinalmember 300 to the proximal end 322 of the longitudinal member 300. Thelens elements 342 are preferably positioned and aligned by the cradle soas to relay an image of the illuminated object or inner wall.

The solid state emitters 326 generate heat as they emit light. The heatis preferably conducted away from the distal end 320 of the longitudinalmember 300 by the heat conducting surface 354 of the outer tube 350. Inother embodiments, other portions of the outer tube, the cradle 340and/or lens holder 328 may comprise thermally conductive material orlayers so as to transfer heat produced by the emitters 326. Increasedthermal conduction permit the emitters 326 to be driven with more powerso as to emit more light. In some embodiments, the LEDs are driven witha current of up to 40 or 60 milliamps or more.

Preferably, the longitudinal member 300 has a small cross-section forexample less than 3 or 4 millimeters across in some embodiments. Thesmall size of the emitters facilitates such small cross-sections. Asdescribed above, the small cross-section reduces trauma and damage tothe body in which the endoscope is inserted.

In various embodiments, the longitudinal member 300 is disposable. Thelenses 342 may comprise compression molded glass, which can bemanufactured relatively inexpensively such that the longitudinal member340 together with the emitters 326 and the lens may be disposed of aftera single use and remain cost-effective in comparison with conventionalendoscope designs. In certain embodiments, the longitudinal member issterilizable.

FIG. 4 is a rear perspective view of an exemplary front lens holder 400for use with a longitudinal member of an endoscope, such as thelongitudinal member 300 shown in FIG. 3. The front lens holder 400comprises a front surface 402, a rear surface 404, and an inner cavityregion 406. The front surface 402 and the rear surface 404 each comprisean aperture to the inner cavity region 406. For illustrative purposes,FIG. 4 shows an optical path 410 entering the aperture on the frontsurface 402, passing through the inner cavity region 406 and out theaperture of the rear surface 404.

The front surface 402 is tilted with respect to the rear surface 404 ofthe front lens holder 400. The tilted front surface 402 allows the frontlens holder 400 to collect light reflected from of objects located tothe side of an endoscope. In exemplary embodiments, the front surface402 is tilted between about 30° and 70° with respect to the rear surface404. In certain embodiments, for example, this tilt may be about 45°.However, it should be noted that the tilt of the front surface 402 canbe selected to provide the user of the endoscope with the ability toview objects located to the side of the endoscope according to anynumber of angle ranges, including but not limited to a flat surfaceparallel to the rear surface 404. In some of these embodiments, solidstate emitters (not shown) located on the front surface 402 may beangled, for example, so as to emit light at an angle to illuminateobjects to the side of the endoscope. The lens (not shown) in the lensholder 400 may also be tilted to collect light reflected or scatteredfrom the sidewalls of the body cavity.

The front lens holder 400 is configured to redirect the light enteringthe front lens holder 400 through the aperture in the front surface 402to exit the front lens holder 400 through the aperture in the rearsurface 404 so as to convey an image of an object along an optical paththrough the endoscope. In certain embodiments, the light entering thefront lens holder 400 is redirected using an optical element such as aprism (not shown) comprising one or more reflective surfaces. In variouspreferred embodiments, however, the light entering the front lens holder400 is redirected using a first reflective surface 420 and a secondreflective surface 422. Preferably, the first and second reflectivesurfaces 420, 422 do not comprise glass. These reflective surfaces 420,422 may comprise a reflective layer such as metallization formed on asurface of the lens holder 400.

FIG. 4 illustrates the first reflective surface 420 and the secondreflective surface 422 walls defining the inner cavity region 406. Thefirst reflective surface 420 and the second reflective surface 422 areangled such that the optical path 410 of the light entering the cavityregion 406 approximately perpendicular to the front surface 402 will beredirected so as to exit the cavity region 406 approximatelyperpendicular to the rear surface 404. Thus, for example, light enteringthe longitudinal member 300 shown in FIG. 3 will be redirected andconveyed through the inner cavity region 324 from the distal end 320 tothe proximal end 322 through the plurality of rod lenses 342.

To illustrate the concept of redirecting light through the front lensholder 400, FIG. 5 shows a schematic diagram of an optical path 508through a front surface 510 tilted at an angle with respect to a rearsurface 512. The optical path 508 passes approximately perpendicularthrough the front surface 510 and intersects with a first reflectivesurface 514 positioned and angled so as to redirect the optical path 508to a second reflective surface 516. The second reflective surface 516 ispositioned and angled so as to redirect the optical path 508approximately perpendicularly through the rear surface 512. In otherembodiments, the front surface 510 and rear surface 512 may not beperpendicular to this optical path 508, however, preferably the firstand second reflective surfaces 514, 516 are oriented to direct theoptical path through the length of the elongated member.

Referring again to FIG. 4, the first and second reflective surfaces 420,422 are substantially specularly reflective. The first and secondreflective surfaces 420, 422 may, for example, be smooth, planarsurfaces. The front lens holder 400 may be formed from materials thatcan be molded or machined. In various embodiments, the front lens holder400 is formed of a material selected from the group comprising plastic,ceramic, or metal such as nickel or the like. In certain preferredembodiments, the first and second reflective surfaces 420, 422 arepolished until they are substantially smooth. For example, the first andsecond reflective surfaces 420, 422 may be polished down to averageroughness of approximately eight Angstroms. After polishing, the firstand second surfaces may be metallized with a substantially reflectivematerial, such as nickel, chrome or the like. Other reflective layersmay be employed as well. In certain embodiments, the substantiallyreflective material is electroplated or electrochemically deposited ontothe polished surfaces. For example, in various exemplary embodiments,the lens holder comprises molded or machined plastic or ceramic that iselectroplated to form reflective metal layers. Nickel electroforming,for example, may be employed to create the first and/or secondreflective surfaces 420, 422. Such processes are well-developed andrelatively inexpensive and can be readily implemented in manufacturingprocesses.

Forming reflective surfaces on the inner walls of the lens holder offersseveral advantages. Integrating the reflective surfaces into the lensholder reduces the number of elements that need to be optically aligned.For example, once the reflective surfaces have been formed on theinterior walls of the lens holder, precise alignment may be achieved bysimply inserting or “snapping” the lens holder 400 in place on thelongitudinal member 300. In contrast, microscopes are employed to aligntiny prisms in conventional designs. These micro-prisms are alsosubstantially more expensive. For example, injection molding the lensholder 400, polishing inner surfaces on the lens holder, and performingNi electroforming or chrome electroplating may be relatively lessexpensive in comparison to polishing tiny glass micro-prisms. Thereduced cost yielded by such designs may permit the endoscope to bedisposable.

FIG. 6 provides another view of a front lens holder 600 for use with alongitudinal member of an endoscope, such as the longitudinal member 300shown in FIG. 3. FIG. 6 is a partial front perspective view of the frontlens holder 600. The front lens holder 600 comprises a front surface 610and a rear surface 612. A hollow interior region 614 extends from anaperture in the front surface 610 to an aperture in the rear surface612. In various embodiments, the front lens holder 600 includes a lensseat 616 configured to hold a lens (not shown) which covers the aperturein the front surface 610. The specifications of the lens, e.g., power,numerical aperture, etc., are preferably selected to direct light intothe front lens holder 600. Alternatively, the aperture in the frontsurface 610 may be covered with a window or material (not shown) that istransparent to selected wavelengths of light. A lens may be disposed inthe inner region 614 of the lens holder 600 or may be exterior to thelens holder in some embodiments. The hollow interior region 614 may behermetically sealed and may be filled with a gas or liquid.Alternatively, the hollow interior region 614 may be a vacuum.

The front surface 610 of the front lens holder 600 includes a pluralityof seats 622 (eight shown) configured to hold solid state emitters (notshown), such as LEDs. The seats 622 are positioned around the aperturein the front surface 610. The seats 622 are positioned such that lightemitted from their respective locations will be reflected from an objectback through the aperture in the front surface 610. In variousembodiments, the seats are arranged to provide substantially uniformillumination.

The front surface 610 also includes a path 624 for electrical power. Inan embodiment, the path 624 is shaped to hold thin electrical wiresconnecting the solid state emitters to an electrical power source.Alternatively, the path 624 comprises a conductive trace for providingpower to the solid state emitters. The path 624 may be connected to oneor more through-holes 626 (two shown) to electrically couple power froma power source (not shown).

As described above, the front lens holder 600 may be formed, forexample, by molding, machining, or other manufacturing processes. Thelens holder may comprise two or more separable pieces that are fittogether. Such designs may facilitate manufacture such as polishing theinner surfaces to form reflective portions of the interior sidewalls. Invarious embodiments, the front lens holder 600 is disposable and/orsterilizable.

FIG. 7 is a perspective view of an elongated support structure 700,which can be used as a cradle, such as the cradle 340 shown in FIG. 3.The elongated support structure 700 comprises a hollow tube 710 having aplurality of slots 712 (five shown) each configured to hold a lens suchas a rod lens (not shown) or other optical element. The slots 712 areseparated by spacer portions 714 (four shown) that are each sized andpositioned so as to provide proper alignment and longitudinal separationof the rod elements for suitable relay of an image therethrough. Inother words, the spacing between the slots 712 are defined by the spacerportions 714 so as to longitudinally space the rod lenses with respectto each other according to the optical design prescription.

The elongated support structure 700 may be formed, for example, bymolding, machining, or other manufacturing processes. The elongatedsupport structure 700 may comprise, for example, plastic, ceramic, ormetal. In certain embodiments, one or more electrical traces or pathsmay be formed on a surface of the elongated support structure 700 toprovide electrical power to solid state light emitters (not shown). Invarious embodiments, the elongated support structure 700 is sterilizableand/or disposable.

FIG. 8 is a partial perspective view of another exemplary slottedelongate support structure 800 which can be used as a cradle, such asthe cradle 340 shown in FIG. 3. The slotted elongate support structurecomprises a hollow tube 810 having slots 812 configured to hold lenssuch as rod lens (not shown) or other optical elements. The slots 812are separated by spacing elements 814 (two shown) that are each sizedand positioned so as to provide proper longitudinal separation of therod elements for suitable propagation of an image. The slots 812 arepreferably positioned to provide proper lateral positioning of the lensor other optical elements as well.

The slotted elongate support structure 800 also includes a tapered “V”shaped portion 820 that is pointed at one end. The tapered “V” shapedportion 820 is configured to facilitate the insertion of the slottedelongate support structure 800 into an outer tube, such as the outertube 350 shown in FIG. 3. When aligning the slotted elongate supportstructure 800 with an outer tube, the point of the “V” shaped member 820is preferably sufficiently small so as to be easily inserted into theouter tube. The “V” shaped member 820 also simplifies the manufacturingprocess by properly aligning the slotted elongate support structure 800with an outer tube upon insertion therein.

The slotted elongate support structure 800 may have other shapes aswell. In certain embodiments, for example, the slotted elongated supportstructure may be “V” shaped having a “V” shaped lateral cross-sectionover a substantial portion of its length.

The features described herein can be employed alone or in variouscombinations to create improved endoscopes designs. For example,endoscope structures having solid state emitters may be employedtogether with a lens holder that does not include a prism.Alternatively, the lens holder designs described herein can be employedwith conventional illumination approaches such as use of a fiber opticbundle instead of LEDs. Similarly, the slotted elongated supportstructure may be employed with or without solid state emitters and withor without the lens holder having reflective interior sidewalls fordirecting an image through an array of lenses. A wide range of designsare possible.

Also, although FIG. 3 depicts rod lenses being disposed in the endoscopestructure, in various embodiments, other types of lenses such as lenseshaving reduced longitudinal thickness may be employed. Rod lensesadvantageously increase optical throughput by increasing the Lagrangeinvariant. However, a plurality of small bright solid state lightemitters, such as LED's, may provide substantially illumination. Thesolid state emitters, together with their electrical power connections,however, do not occupy as much area across a lateral cross-section ofthe endoscope structure as a fiber optic bundle used for illumination inconventional endoscope designs. Accordingly, room is available forlarger diameter lenses having higher numerical aperture and throughputwhen using tiny solid stated emitters. With increased throughput, lensesthinner than rod lens may be employed. The reduced Lagrange invariant isoffset by the increase in diameter of the lenses. The throughput may belarger in some cases where thin lenses are employed instead of rodlenses. Likewise, rod lenses may or may not be employed in combination,for example, with the lens holder having internal reflecting sidewallsand/or the slotted elongate support structure. For example, in certainembodiments, the elongate support structure may have slots with reducedlength to accommodate lenses other than rod lenses. In general, rodlenses are more expensive than thin lenses. Accordingly, themanufacturing cost of the endoscope can be reduced.

As described above, various combination and arrangements may beemployed. Accordingly, the structures and apparatus should not belimited to those particular designs shown in FIGS. 1-8 or specificallydisclosed in the description of these figures. Other embodiments arepossible as well. These embodiments may include features well known inthe art as well as feature not yet devised.

As described above, the process of manufacturing the endoscope devicesmay be simplified or improved. In certain embodiments, for instance, thelenses can be automatically positioned in the cradle so as to havesuitable spacing between lenses to relay an image in the body. Such amethod of forming an endoscope apparatus having proximal and distal endsmay comprise, for example, providing an elongated support structurehaving a plurality of sites for insertion of optical elements andinserting a plurality of lenses at the sites. The elongated supportstructure may be inserted into a hollow outer protective shield havingan open inner region. Preferably, the plurality of sites are laterallypositioned and longitudinally spaced with respect to each other so as toprovide an aligned optical system that relays an image from the distalend portion to the proximal end portion. Such manufacture may beimplemented partially or totally robotically in certain cases. Suchautomated processes may reduce the cost of manufacture.

In other various embodiments, a front endpiece may be attached at thedistal end portion of an endoscope assembly. The front endpiecepreferably has an open inner region for receiving light to form imagesof portions of a body. A plurality of solid state light emitters arepreferably affixed to the front endpiece to illuminate the bodyportions. A lens is mounted to the front endpiece to receive light fromthe body portions. At least one reflective surface is formed on asidewall of the inner open region of the front endpiece to reflect lightreceived from the body portions through the plurality of lenses.

Other manufacturing methods may include molding the front endpiece so asto include the sidewall surface on the inner open region for forming thereflective surface with a shape and orientation to produce the image.The reflective surface may be formed by metalizing the sidewall surface.In certain embodiments, the sidewall surface is polished prior tometallization.

In other embodiments, a method for manufacturing a front end of anendoscope for viewing portions of a body comprises forming a frontendpiece for receiving light from the body portions so as to enableviewing of the body portions. An inner cavity region is formed in thefront endpiece to allow passage of the light from the body portions andat least one substantially planar sidewall surface is formed in theinner cavity region. The method also includes metalizing the at leastone substantially planar sidewall surface so as to form a substantiallyreflective surface that reflects the light received from the bodyportions. The sidewall surface may be polished prior to metallization tocreate a substantially smooth surface.

At least one seat is preferably formed in the front endpiece forplacement of one or more solid state light emitters to illuminate thebody portions. A lens seat may be formed in the front endpiece formounting a lens to receive light from the body portions. In certainembodiments, the front endpiece is formed by molding. In someembodiments, at least a portion of the front endpiece is formed bymachining.

Various combinations of manufacturing steps may be employed with more orless steps and the specific method should not be limited to the specificprocesses recited herein. A wide range of fabrication methods arepossible.

While the present invention has been disclosed in detail and by way ofexemplary embodiments, those of ordinary skill in the art will recognizeand appreciate that the invention is not so limited. Those of ordinaryskill in the art will recognize and appreciate that many additions,deletions and modifications to the disclosed embodiment and itsvariations may be implemented without departing from the scope of theinvention, which is limited only by the appended claims and their legalequivalents.

What is claimed is:
 1. An endoscope having proximal and distal endportions for viewing features inside a body, said endoscope comprising:a plurality of rod lenses aligned along an optical path; a slottedelongated support structure comprising a plurality of slots in whichsaid plurality of rod lenses respectively fit so as to be aligned alongsaid optical path; and an outer tube with a hollow inner region, saidslotted elongated support structure together with said plurality of rodlenses disposed in said hollow inner region of said out tube; whereinsaid slots are separated with respect to each other so as to establishsuitable spacing between said rod lenses to relay an image of a featurein said body to said proximal end portion.
 2. The endoscope of claim 1,wherein said slotted elongated support structure comprises a hollowcylindrical tube with portions of said tube removed to form saidplurality of slots in which said plurality of rod lenses respectivelyfit.
 3. The endoscope of claim 1, wherein said slotted elongated supportstructure comprises a “V” shaped member, with portions of said memberopen to create said plurality of slots in which said plurality of rodlenses respectively fit.
 4. The endoscope of claim 1, wherein saidslotted elongated support structure is pointed at one end to facilitateinsertion of said slotted elongate support structure in said outer tube.5. The endoscope of claim 1, wherein said plurality of rod lensescomprises compression molded lenses.
 6. The endoscope of claim 1,further comprising a front endpiece at said distal end portion of saidendoscope, said front endpiece having an open inner region for receivinglight to form images of said body features.
 7. The endoscope of claim 6,wherein said front endpiece further comprises a plurality of solid statelight emitters for illuminating said body features.
 8. The endoscope ofclaim 6, wherein said front endpiece further comprises a lens configuredto receive light from said body features.
 9. The endoscope of claim 6,wherein said front endpiece further comprises at least one reflectivesurface on a sidewall of said inner open region to reflect lightreceived from said body features through said plurality of rod lenses.10. The endoscope of claim 9, wherein said front endpiece is molded toinclude said reflective surface having a shape and orientation toproduce said image.
 11. The endoscope of claim 10, wherein said sidewallsurface is polished.
 12. The endoscope of claim 10, wherein saidsidewall surface is metalized to form said reflective surface.